/*
silverPDF is sponsored by Aleyant Systems (http://www.aleyant.com)

silverPDF is based on PdfSharp (http://www.pdfsharp.net) and iTextSharp (http://itextsharp.sourceforge.net)

Developers: Ai_boy (aka Oleksii Okhrymenko)

Permission is hereby granted, free of charge, to any person
obtaining a copy of this software and associated documentation
files (the "Software"), to deal in the Software without
restriction, including without limitation the rights to use,
copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the
Software is furnished to do so, subject to the following
conditions:

The above information and this permission notice shall be
included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR SPONSORS
BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
OTHER DEALINGS IN THE SOFTWARE.

*/
#region PDFsharp - A .NET library for processing PDF
//
// Authors:
//   Stefan Lange (mailto:Stefan.Lange@pdfsharp.com)
//
// Copyright (c) 2005-2008 empira Software GmbH, Cologne (Germany)
//
// http://www.pdfsharp.com
// http://sourceforge.net/projects/pdfsharp
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the "Software"),
// to deal in the Software without restriction, including without limitation
// the rights to use, copy, modify, merge, publish, distribute, sublicense,
// and/or sell copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
// THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 
// DEALINGS IN THE SOFTWARE.
#endregion

using System;
using System.Diagnostics;
using System.Collections;
using PdfSharp.Pdf;
using PdfSharp.Internal;
using PdfSharp.Drawing;

namespace PdfSharp.Pdf.Annotations
{
  /// <summary>
  /// Represents the base class of all annotations.
  /// </summary>
  public abstract class PdfAnnotation : PdfDictionary
  {
    /// <summary>
    /// Initializes a new instance of the <see cref="PdfAnnotation"/> class.
    /// </summary>
    protected PdfAnnotation()
    {
      Initialize();
    }

    /// <summary>
    /// Initializes a new instance of the <see cref="PdfAnnotation"/> class.
    /// </summary>
    protected PdfAnnotation(PdfDocument document)
      : base(document)
    {
      Initialize();
    }

    /// <summary>
    /// Initializes a new instance of the <see cref="PdfAnnotation"/> class.
    /// </summary>
    internal PdfAnnotation(PdfDictionary dict)
      : base(dict)
    {
    }

    void Initialize()
    {
      Elements.SetName(Keys.Type, "/Annot");
      Elements.SetString(Keys.NM, Guid.NewGuid().ToString("D"));
      Elements.SetDateTime(Keys.M, DateTime.Now);
    }

    //dmh - 6/7/06 added delete method
    /// <summary>
    /// Removes an annotation from the document
    /// <seealso cref="PdfAnnotations.Remove(PdfAnnotation)"/>
    /// </summary>
    [Obsolete("Use 'Parent.Remove(this)'")]
    public void Delete()
    {
      Parent.Remove(this);
    }

    /// <summary>
    /// Gets or sets the annotation flags of this instance.
    /// </summary>
    public PdfAnnotationFlags Flags
    {
      get { return (PdfAnnotationFlags)Elements.GetInteger(Keys.F); }
      set
      {
        Elements.SetInteger(Keys.F, (int)value);
        Elements.SetDateTime(Keys.M, DateTime.Now);
      }
    }

    /// <summary>
    /// Gets or sets the PdfAnnotations object that this annoation belongs to.
    /// </summary>
    public PdfAnnotations Parent
    {
      get { return this.parent; }
      set { this.parent = value; }
    }
    PdfAnnotations parent;

    /// <summary>
    /// Gets or sets the annotation rectangle, defining the location of the annotation
    /// on the page in default user space units.
    /// </summary>
    public PdfRectangle Rectangle
    {
      get { return Elements.GetRectangle(Keys.Rect, true); }
      set
      {
        Elements.SetRectangle(Keys.Rect, value);
        Elements.SetDateTime(Keys.M, DateTime.Now);
      }
    }

    /// <summary>
    /// Gets or sets the text label to be displayed in the title bar of the annotation�s
    /// pop-up window when open and active. By convention, this entry identifies
    /// the user who added the annotation.
    /// </summary>
    public string Title
    {
      get { return Elements.GetString(Keys.T, true); }
      set
      {
        Elements.SetString(Keys.T, value);
        Elements.SetDateTime(Keys.M, DateTime.Now);
      }
    }

    /// <summary>
    /// Gets or sets text representing a short description of the subject being
    /// addressed by the annotation.
    /// </summary>
    public string Subject
    {
      get { return Elements.GetString(Keys.Subj, true); }
      set
      {
        Elements.SetString(Keys.Subj, value);
        Elements.SetDateTime(Keys.M, DateTime.Now);
      }
    }

    /// <summary>
    /// Gets or sets the text to be displayed for the annotation or, if this type of
    /// annotation does not display text, an alternate description of the annotation�s
    /// contents in human-readable form.
    /// </summary>
    public string Contents
    {
      get { return Elements.GetString(Keys.Contents, true); }
      set
      {
        Elements.SetString(Keys.Contents, value);
        Elements.SetDateTime(Keys.M, DateTime.Now);
      }
    }

    /// <summary>
    /// Gets or sets the color representing the components of the annotation. If the color
    /// has an alpha value other than 1, it is ignored. Use property Opacity to get or set the
    /// opacity of an annotation.
    /// </summary>
    public XColor Color
    {
      get
      {
        PdfItem item = Elements[Keys.C];
        if (item is PdfArray)  // TODO: check for iref?
        {
          PdfArray array = (PdfArray)item;
          if (array.Elements.Count == 3)
          {
            // TODO: an array.GetColor() function may be useful here
            return XColor.FromArgb(
              (int)(array.Elements.GetReal(0) * 255),
              (int)(array.Elements.GetReal(1) * 255),
              (int)(array.Elements.GetReal(2) * 255));
          }
        }
        return XColors.Black;
      }
      set
      {
        // TODO: an array.SetColor(clr) function may be useful here
        PdfArray array = new PdfArray(this.Owner, new PdfReal[] 
          { new PdfReal(value.R / 255.0), new PdfReal(value.G / 255.0), new PdfReal(value.B / 255.0) });
        Elements[Keys.C] = array;
        Elements.SetDateTime(Keys.M, DateTime.Now);
      }
    }

    /// <summary>
    /// Gets or sets the constant opacity value to be used in painting the annotation.
    /// This value applies to all visible elements of the annotation in its closed state
    /// (including its background and border) but not to the popup window that appears when
    /// the annotation is opened.
    /// </summary>
    public double Opacity
    {
      get
      {
        if (!Elements.Contains(Keys.CA))
          return 1;
        return Elements.GetReal(Keys.CA, true);
      }
      set
      {
        if (value < 0 || value > 1)
          throw new ArgumentOutOfRangeException("value", "Opacity must be a value in the range from 0 to 1.");
        Elements.SetReal(Keys.CA, value);
        Elements.SetDateTime(Keys.M, DateTime.Now);
      }
    }

    /// <summary>
    /// Predefined keys of this dictionary.
    /// </summary>
    public class Keys : KeysBase
    {
      /// <summary>
      /// (Optional) The type of PDF object that this dictionary describes; if present,
      /// must be Annot for an annotation dictionary.
      /// </summary>
      [KeyInfo(KeyType.Name | KeyType.Optional, FixedValue = "Annot")]
      public const string Type = "/Type";

      /// <summary>
      /// (Required) The type of annotation that this dictionary describes.
      /// </summary>
      [KeyInfo(KeyType.Name | KeyType.Required)]
      public const string Subtype = "/Subtype";

      /// <summary>
      /// (Required) The annotation rectangle, defining the location of the annotation
      /// on the page in default user space units.
      /// </summary>
      [KeyInfo(KeyType.Rectangle | KeyType.Required)]
      public const string Rect = "/Rect";

      /// <summary>
      /// (Optional) Text to be displayed for the annotation or, if this type of annotation
      /// does not display text, an alternate description of the annotation�s contents
      /// in human-readable form. In either case, this text is useful when
      /// extracting the document�s contents in support of accessibility to users with
      /// disabilities or for other purposes.
      /// </summary>
      [KeyInfo(KeyType.TextString | KeyType.Optional)]
      public const string Contents = "/Contents";

      // P

      /// <summary>
      /// (Optional; PDF 1.4) The annotation name, a text string uniquely identifying it
      /// among all the annotations on its page.
      /// </summary>
      [KeyInfo(KeyType.TextString | KeyType.Optional)]
      public const string NM = "/NM";

      /// <summary>
      /// (Optional; PDF 1.1) The date and time when the annotation was most recently
      /// modified. The preferred format is a date string, but viewer applications should be 
      /// prepared to accept and display a string in any format.
      /// </summary>
      [KeyInfo(KeyType.Date | KeyType.Optional)]
      public const string M = "/M";

      /// <summary>
      /// (Optional; PDF 1.1) A set of flags specifying various characteristics of the annotation.
      /// Default value: 0.
      /// </summary>
      [KeyInfo("1.1", KeyType.Integer | KeyType.Optional)]
      public const string F = "/F";

      /// <summary>
      /// (Optional; PDF 1.2) A border style dictionary specifying the characteristics of
      /// the annotation�s border.
      /// </summary>
      [KeyInfo("1.2", KeyType.Dictionary | KeyType.Optional)]
      public const string BS = "/BS";

      /// <summary>
      /// (Optional; PDF 1.2) An appearance dictionary specifying how the annotation
      /// is presented visually on the page. Individual annotation handlers may ignore
      /// this entry and provide their own appearances.
      /// </summary>
      [KeyInfo("1.2", KeyType.Dictionary | KeyType.Optional)]
      public const string AP = "/AP";

      /// <summary>
      /// (Required if the appearance dictionary AP contains one or more subdictionaries; PDF 1.2)
      /// The annotation�s appearance state, which selects the applicable appearance stream from 
      /// an appearance subdictionary.
      /// </summary>
      [KeyInfo("1.2", KeyType.Dictionary | KeyType.Optional)]
      public const string AS = "/AS";

      /// <summary>
      /// (Optional) An array specifying the characteristics of the annotation�s border.
      /// The border is specified as a rounded rectangle.
      /// In PDF 1.0, the array consists of three numbers defining the horizontal corner 
      /// radius, vertical corner radius, and border width, all in default user space units.
      /// If the corner radii are 0, the border has square (not rounded) corners; if the border 
      /// width is 0, no border is drawn.
      /// In PDF 1.1, the array may have a fourth element, an optional dash array defining a 
      /// pattern of dashes and gaps to be used in drawing the border. The dash array is 
      /// specified in the same format as in the line dash pattern parameter of the graphics state.
      /// For example, a Border value of [0 0 1 [3 2]] specifies a border 1 unit wide, with
      /// square corners, drawn with 3-unit dashes alternating with 2-unit gaps. Note that no
      /// dash phase is specified; the phase is assumed to be 0.
      /// Note: In PDF 1.2 or later, this entry may be ignored in favor of the BS entry.
      /// </summary>
      [KeyInfo(KeyType.Array | KeyType.Optional)]
      public const string Border = "/Border";

      /// <summary>
      /// (Optional; PDF 1.1) An array of three numbers in the range 0.0 to 1.0, representing
      /// the components of a color in the DeviceRGB color space. This color is used for the
      /// following purposes:
      /// � The background of the annotation�s icon when closed
      /// � The title bar of the annotation�s pop-up window
      /// � The border of a link annotation
      /// </summary>
      [KeyInfo("1.1", KeyType.Array | KeyType.Optional)]
      public const string C = "/C";

      /// <summary>
      /// (Optional; PDF 1.1) An action to be performed when the annotation is activated.
      /// Note: This entry is not permitted in link annotations if a Dest entry is present.
      /// Also note that the A entry in movie annotations has a different meaning.
      /// </summary>
      [KeyInfo("1.1", KeyType.Dictionary | KeyType.Optional)]
      public const string A = "/A";

      // AA
      // StructParent
      // OC

      // ----- Excerpt of entries specific to markup annotations ----------------------------------

      /// <summary>
      /// (Optional; PDF 1.1) The text label to be displayed in the title bar of the annotation�s
      /// pop-up window when open and active. By convention, this entry identifies
      /// the user who added the annotation.
      /// </summary>
      [KeyInfo(KeyType.TextString | KeyType.Optional)]
      public const string T = "/T";

      /// <summary>
      /// (Optional; PDF 1.3) An indirect reference to a pop-up annotation for entering or
      /// editing the text associated with this annotation.
      /// </summary>
      [KeyInfo(KeyType.Dictionary | KeyType.Optional)]
      public const string Popup = "/Popup";

      /// <summary>
      /// (Optional; PDF 1.4) The constant opacity value to be used in painting the annotation.
      /// This value applies to all visible elements of the annotation in its closed state
      /// (including its background and border) but not to the popup window that appears when
      /// the annotation is opened.
      /// The specified value is not used if the annotation has an appearance stream; in that
      /// case, the appearance stream must specify any transparency. (However, if the viewer
      /// regenerates the annotation�s appearance stream, it may incorporate the CA value
      /// into the stream�s content.)
      /// The implicit blend mode is Normal.
      /// Default value: 1.0.
      /// </summary>
      [KeyInfo(KeyType.Real | KeyType.Optional)]
      public const string CA = "/CA";

      //RC
      //CreationDate
      //IRT

      /// <summary>
      /// (Optional; PDF 1.5) Text representing a short description of the subject being
      /// addressed by the annotation.
      /// </summary>
      [KeyInfo("1.5", KeyType.TextString | KeyType.Optional)]
      public const string Subj = "/Subj";

      //RT
      //IT
    }
  }
}
